Hi all: I've installed a debian server and all works great. I've followed this tutorial: http://www.howtoforge.org/perfect-server-debian-lenny-ispconfig3 In my server I have only one domain and about ten mailboxes for this domain. Now I have a lot of problems because one or two mailboxes can't receive some messages. The error shown on sender mail program is: Failed: 5.4.0 (other or undefined network or routing status) Is it a postfix configuration problem? smtp problem? a problem on network server? Thanks a lot for your help!